There has been a problem that, when an image of an outdoor scene is captured from an indoor location, a subject is darkened against a bright background and is difficult to see. As a solution to such a problem, plural techniques to brighten a captured image output from an imaging unit have been known.
There has been, for example, a backlight correction process in which a captured image is brightened by performing gain correction and the like of the captured image. Further, a wide dynamic range process has been known in which multiple captured images are synthesized and the synthesized image having a wide dynamic range is obtained. PTL 1 discloses a technique of synthesizing multiple captured images with different exposure times to generate a captured image with a dynamic range wider than normal.
As an example of the techniques mentioned above, in silver salt photography, there has been a dodging process performed in a darkroom for obtaining a photograph with a wide dynamic range. There has been a technique (digital dodging process) which is realized by applying the dodging process to a digital image process, in which a captured image of a subject having a large difference between brightness and darkness, particularly a subject under backlight, is corrected. Further, in the digital dodging process, in order to adjust the intensity of the process, the gain and the like of a captured image are changed.
As another example of the techniques mentioned above, a process has been known which outputs a captured image with a subject that is easily identifiable, by employing a process of exposure correction of a single captured image.
Further, in recent years, there has been a case where a single imaging apparatus is provided with those multiple processes. In addition, with a rapidly spreading network technology, there has been an increasing user's need for controlling such an imaging apparatus from an external apparatus through a network.
However, in the imaging apparatus described above, a captured image becomes too bright in some cases when those multiple processes are performed simultaneously. For example, when a backlight correction process, a wide dynamic range process, and a digital dodging process are performed on a captured image at the same time, the captured image may become too bright.
Further, whether or not a captured image becomes too bright due to the simultaneous execution of those multiple processes on the captured image, depends on a subject. When it is assumed that the above-described imaging apparatus captures an image of an outdoor scene or that a subject moves during imaging, the subject image changes constantly.
Furthermore, with the imaging apparatus described above, whether or not the captured image becomes too bright also depends on the degree at which each of the processes brightens the captured image. However, the degree at which each of the processes brightens the captured image varies according to the model of the imaging apparatus or the manufacturer of the imaging apparatus.
Therefore, in the case where the imaging apparatus described above is installed at a place remote from a user, it is difficult for the user operating an external apparatus to control individual performances of processes in an attempt to prevent the captured image from becoming too bright, while taking into account changes of a subject of the imaging apparatus and the model or manufacturer of the imaging apparatus.